Electrical repeater tube



Sept. 4, 1934.

A. MCL. NICOLSON ELECTRICAL REPEATER TUBE Filed March 22, 1932 INVENTOR Alexander M Lean Ninnlsun ATTORNEY Patented Sept. 4, 1934 PATENT OFFICE 1,972,491 ELECTRICAL REPEATER TUBE Alexander Mcl lean Nicolscn, New York, N. Y., as-

signor to Communication Patents, Inc, New York, N. Y., a corporation of Delaware Application March 22, 1932, Serial No. 600,438

r 9 Claims. (01. 250- 275) amplify electrical currents in 'a discharge device having no thermionically active element.

A further object of the invention is to control the ionization produced by a piezoelectric crystal in vibration and to employ such a device as a detector or amplifier of electrical signals.

Vacuum tube amplifiers of' many types are well" known such as those commonly used in radio communications in whicha thermionically'active elementand a plurality of cold electrodes are positionedin an evacuated envelope. known in the art how a similar repeater tube may be constructed utilizing solely cold electrodes,

2 and in which. the gas is ionized by a potential difference between two electrodes. Such discharge tubes have been used as radio and audiofrequenc amplifiers and detectors .of radio signals.

One other feature of the present invention is familiar to those skilled in the art and that is,

the production of ionization by a vibrating piezo electric crystal element in a partial vacuum. The regions of ionization form various patterns around 3 and about the crystal depending upon the manner used as frequency'indicators and for other like purposes but in .the' present invention theglow produced by the crystal is controlled by an anode and control electrode ora combination thereof; so that the combination functions as a repeater tube similar in. operation to those mentioned above. i 4 The invention in brief contemplates placing a piezoelectric crystal in an envelope evacuated to a pressure of several millimeters of-mercury, the

envelope containing either neon, helium, nitrogen, or a mixture thereof. placed on.the crystals in suitable positions to produce the greatest amount of ionization.

Apositive anode isplaced near the crystal but separated by a control electrode to control the flow of negative ions to the-positive electrode.

It is also 'in which the crystal is cut, and the positioning of the electrodes thereon. Such crystals have been The electrodes are 4 trode 14. The invention will be more fully understoodby reference to the following description taken in conjunction with the drawing in which: Figs. 1, 2 and 3, show different modifications of repeater tubes employing the principles of the invention; I Figs. 4, 5, 6, 7, 8, 9, and 10 show detailed mountings of crystals which serve as ionization sourcesfor tubes and which may be employed inthe systems of Figs. "1, 2 and 3; and, V Fig. 11 shows an embodiment of the invention- With the energizing electrodesoutside the tube.

Referring specifically to Fig. 1, a glass envelope 5 having a press 7 is mounted upon a base 6. In the press '7 are four seal-in conductors, two of which connectto two electrodes 9 and 10 for a crystal 12, the conductors being sufficiently rigid to support the crystal in the position shown. An anode element 13 is shown in the form of a flat plate but may be a cylinder surrounding the crystal 12-and its electrodes. The third element in the envelope 5fis a control electrode 14 which is positioned between the crystal 12 and anode 13 and which may be in the form of a mesh plate or meshed cylinder surrounding "the crystal. These elements are mounted inthe usual manner well known in the art'of thermionic'tube construction.

The respective connections of the electrodes above mentioned to certain external elements are shown for purposes of explaining their function. Electrodes 9 and 10 are connected across a source. of alternating current 16 which is shunted by a. potentiometer resistance 17 The source 16 supplies to the crystal 12 a voltage having a frequency of approximately that of the crystal; the frequency of the source being adjustable by means of a variable condenser 18, although it is to be understood that the crystal will produce ionization-at other frequencies. The anode 13 is connected through an output inductance 20, which may represent any. form of output circuit commonly known in the art, to a variable contact 21 on the resistance 17. To this same contact, the control electrode 14 is connected through an input inductance 23.. The

anode and'control electrode polarizing batterie are shown as 24 and 25,- respectively.

This tube operates in substantially the same manner as the ordinary tube and could be used in any receiver having tubes withcathode's supplied from an alternating source. The negative ions and electrons produced by ionization of the gas by crystal vibration are attracted to the anode-13, this attraction being controlled by the static and dynamic polarizing of thecontrol elec- Theimounting shown in Fig. 1 is of one particular type such type being a crystal of cylindrical shape having thereon an even number of alternatively connected electrodes. In this manner potentials are distributed at the pole faces producing an efficient ionization element.

Now referring to Fig. 2, a second method of mounting the crystal is illustrated. -An envelope 2'7 has a press 28 supporting electrodes 29 and 30 which in turn support a square or rectangular shaped crystal element 31. The electroles 29 and 30 may be cup-shaped so as to hold the crystal there n loosely, the vibration thereof producing a glow between the electrodes on the face of the crystal. In the envelope 27are also an anode 33 and a control electrode 34 mounted on. the press 28 in the same manner as that shown in Fig. 1. The four conductors from this tube may connect in the circuit shown in Fig. l-in similar manner or may be connected in any equivalent circuit.

In Fig. 3 a tube envelope 36 has positioned therein only two elements, one being a crystal 3'7 with its two electrodes 33 and 39, and the other 43 and 4:4 and three electrodes 45, 46 and 47 'Electrodes ,45 and 4:? are connected to the terrninals of the secondary of. atranstormer .49 while the electrode 46flS connected at the mid-tap thereof. This constructionpermits exposing large surfaces of the crystal to the gasto produce ionization. The transformer 49 may be supplied from an alternating current source 50. e

InFig. 5 two crystal sections 52 and 53- shown by" the difierent directions of cross hatching are held together by means of apin 54- of metal, glass or lavite. metal electrodes 55 and 56 are inserted between the sections during their assembly, the electrodes applying to the crystals the potentials necesary to produce ionization. The electrodes usedv in any of the constructions of this invention may be comprised of aluminium, copper or platinum with satisfactory results. The electrodes 55 and 55 are supplied from the alternator 57.

It has been found in the production of ionization by crystal oscillations-that it is advisable in some cases to have the electrodes positioned awayfrom the. crystal to allow the crystal more freedom of vibration, this. distance being approximately one millimeter. In Fig. 6, such a construction is illustrated wherein a crystal 60 is shown ene circled by bands 61 of insulatingv material such as glass or lavite, upon whiclr' are placed, perforated electrodes 62' ended, the perforations being advisable to permitthe ions to more readily circulate about the crystal; The crystal may be cylindrical, rectangular, or square. The: electrodes may be polarized from asourceofi'alternating po-- tentl'al 65. I v

In 7 another construction showing elec trodes positioned away from the crystal is illustrated in which a crystal 6-7" has an insulating bead 'SSplaced in a hole through the crystal and, upon which is fastened electrodes Gil-and '70 which are polarized from source '71.

In Fig. 8' a construction is shown. similar to that of Fig. 5. In this embodiment, a crystal has two sections '72 and 73 shown by the different directions of cross hatching bolted or cemented together with an electrode '74 therebetween, and a second electrode 75 attached to one of the external faces of a section, the electrodes being supplied from, asource 76.. This construction provides a large open face for ionization and is particularly eificient.

In Fig. 9, flat crystal plates and 81 are mountedon supports 82 and 83 of insulating material such as glass or lavite. Electrodes 85 and 86 for theplates are mounted similar to those in Fig. 8 but do. not touch the crystals since they are fastened to the supports 82 and 83. This construction provides absolute freedom of vibration for crystal 86, the vibration of crystal 81 being trans- --n1itted"to crystal 80 through the end supports.

Thisstructure may be polarized from a source 87.

In Fig. 10 a cylindrical piezoelectric crystal 90 has an electrode 91 placed around it asa cylinder, and an electrode 92 placed at one end thereof, as a flat plate, these electrodes being polarized from a source 953. Ionization in such a crystal construction will be produced, at the free end of the crystal-in the well known manner. a

The modification in. Fig. 11 varies from the constructions in Figs. 1, 2 and 3, by employing an envelope 95 in which a recess has been formed to accommodate a crystal cathode 96. The crystal is energized from electrodesi97- and 98 mounted on the outside surface of the recess or adjacent thereto, this connection leaving an unobstructed ionization surface for thecrystal, A control electrode 99 anode 100, and an anode return electrode 161, constitute the other elements within the tube. 'I'heelectrode 101 maybe against the crystal or only within the ionizedregion to complete the output circuit for thisarrangement.

' Although several typesof crystal mountings for use as cathodes have been. shown, it is to be understood that there are other mountings and supports for crystals which will produce ionization but that any such equivalent constructions, when used with anodes andc'ontr'ol electrodes as disclosed aboveyare deemed. to be within the scope of the appended claims.

What is claimedis: V

1. An electrical repeating device comprising a pair of electrodes adapted tobe connected to an alternating voltage source, enclosing means for said electrodes, a gas in said enclosing means, an

ionization element positioned between said electrodes to ionize said. gas when said alternating current source is connected thereto, an anode elecrode and a separate control electrode positioned between, said ionization element and said anode to control the flow of. current from saidelement to said anode in'accordance with the voltage on said control electrode.

2'. An electrical repeating device comprising a partially evacuated envelopaa pair of electrodes located in said envelope adapted to be connected to an alternating current source, a gas in said envelope, a piezoelectric crystal element positioned betweensaid' electrodes for ionizing said gas when said electrodes are-connected to said alternatingcurrent source, an anode electrode,

and a'separate control electrode positioned be-- tween said ionization element and said anode.

3. An electrical detecting device comprising a partially evacuated envelope, a gas insaidenvelope, a piezoelectric crystal element for ionizing said-gas, electrodesfor said crystal element,-

means for connecting-said. electrodes to an alterlkli lee

nating voltage supply, an anode electrode positioned in proximity to said crystal, and a separate control electrode positioned between said crystal electrodes and said anode electrode.

l. An electrical amplifying device comprising a partially evacuated envelope, a piezoelectric crystal element, electrodes for said element adapted to be connected to an alternating voltage supply, an anode element located within said envelope, and a separate fourth electrode within said envelope positioned intermediate said crystal elec trodes and said anode element for controlling the discharge of current from said crystal element to said anode.

5. An electrical repeating device comprising a partially evacuated envelope containing anionizable gas, a pair of electrodes located in said envelope, means intermediate said electrodes for producing ionization of said gas an anode, and means within said envelope indep'endentof said pair of electrodes and said anode for controlling the flow of ions in said gas after their production.

6. An electrical repeating device comprising a partially evacuated envelope containing an ionizable gas, a pair of electrodes located within said envelope, a piezoelectric crystal element positioned between said electrodes for producing ionization of said gas when polarized, an anode trodes having mounted thereon a plurality of piezoelectric crystal elements, and means fastening said elements together around said electrodes.

9. An ionization element for use in a partially evacuated envelope having an ionizable gas, comprising a pair of piezoelectric elements, a pair of insulating supports for said elements, an electrode positioned between said piezoelectric elements and out of contact therewith, and a second electrode positioned near one face of one of said elements, the vibration of said piezoelectric element between said electrodes being transmitted from said piezoelectric element to said other piezoelectric element through said supports.

ALEXANDER MCLEAN NICOLSON. 

